Field of the Invention
The present invention relates to an imaging apparatus and, more particularly, to an exposure control technique of an imaging apparatus which can obtain a plurality of parallactic images.
Description of the Related Art
In the related arts, an automation of exposure (what is called AE) has been considered in a case where an imaging apparatus is automated. In recent years, many systems for obtaining two or more parallactic images have been proposed and techniques about exposure control of them have also been proposed. For example, Japanese Patent Application Laid-Open No. 2012-124622 discloses such a photographing system having a plurality of imaging apparatuses that an object is photographed under different exposure conditions of those imaging apparatuses and, thereafter, photographed images are combined by an image processing.
Japanese Patent Application Laid-Open No. 2011-197278 discloses such an imaging system that a program diagram is designed so as to give a priority to a parallax and a parallax-priority exposure condition is determined.
A camera system which can obtain light field information has been disclosed in Ren Ng, et al., “Light Field Photography with a Hand-held Plenoptic Camera”, 2005, Computer Science Technical Report CTSR. A method of performing a focus adjustment (what is called refocus) after an image is obtained is disclosed in such a system.
However, according to the related art disclosed in the foregoing Patent Literature, a desired exposure is not necessarily obtained in the system which can simultaneously obtain many parallactic images from one imaging element. In other words, although the invention disclosed in Japanese Patent Application Laid-Open No. 2012-124622 can be applied to an imaging system (that is, multocular camera) in which a plurality of imaging apparatuses are combined, it is not easily implemented in a monocular camera.
According to the invention disclosed in Japanese Patent Application Laid-Open No. 2011-197278, although such an idea that there is a parallax-priority function can be realized, it cannot cope with a case where a complex vignetting of a photographing optical system exists, or the like.
According to the invention disclosed in Ren Ng, et al., “Light Field Photography with a Hand-held Plenoptic Camera”, 2005, Computer Science Technical Report CTSR, although an idea such as refocus, change in iris value, or the like is widely disclosed, nothing is disclosed about how to determine the exposure condition when obtaining the light field information.
It is, therefore, an aspect of the invention to provide an imaging apparatus in which even in a state where there is a vignetting in a photographing optical system, an exposure condition corresponding to a function which has preferentially been set by the user can be determined.